The present invention relates to a pump intended for dispensing a liquid or semi-liquid product, particularly a cosmetic or dermo-pharmaceutical product. Such a product may be in the form of a milk, an emulsion, a gel, or a cream. The invention also relates to a device for containing and dispensing a product including such a pump.
U.S. Pat. No. 3,973,700 discloses a sprayer having a body obtained by molding a plastic or a rubber. The body contains a chamber and has a pump including a bellows piston assembly. The bellows allows the volume of the chamber to be varied. The body also contains a nondeformable portion located opposite the bellows, in which two orifices are formed. The orifices are closed off by two flaps obtained by molding with the body. In the closed position, the flaps rest on a seat formed by the edge of the orifice with which they are associated. One of the flaps is formed inside the chamber, and the other is formed outside the chamber. Because of the configuration and positioning of the flaps, the body is molded in the open position, and is closed when mounted on the pump. This configuration poses sealing problems in the chamber closure region, making the fitting of such a pump appreciably more complicated.
Furthermore, because of demands associated with the molding of such flaps, the flaps are positioned in such a way that their one-way operation is not optimal. In particular, the inlet flap is arranged on a wall directed at approximately 45xc2x0 with respect to the direction of the actuating force that has to be exerted on the bellows-forming part via a trigger. This arrangement carries the risk of opening slightly under the effect of a raised pressure in the chamber, thus appreciably minimizing the performance of such a pump.
Other bellows-type mechanisms are known, for example, International Application No. WO 95/00253 and U.S. Pat. No. 5,829,640. In these documents, the inlet and outlet orifices are closed by flaps in the form of attached elements separate from an elastically deformable part that forms at least part of the chamber. This arrangement results in a pump that is complicated to fit and expensive to implement.
A pump having a portion of rubber that is formed by assembling two or more parts, is described in U.S. Pat. No. 2,772,817. The pump disclosed in this reference may suffer from one or more of the disadvantages described above.
According to one aspect of the invention, a pump may include a single-piece vessel of unitary construction defining a variable-volume chamber. The vessel may include a first wall and a second wall. The first wall may include an inlet slit formed therein, and the second wall may include an outlet slit formed therein. The inlet slit may be configured to open one way in response to a decreased pressure in the chamber, and the outlet slit may be configured to open one way in response to an increased pressure in the chamber.
In one embodiment, the vessel may be configured to deform from a first position occupying a first volume to a second position occupying a second volume in response to a pressure applied to the vessel. The first volume may be a maximum and the second volume may be a minimum. Optionally, the pump may include an actuating member configured such that a pressure on the actuating member transmits the pressure to the vessel.
The vessel may be formed, for example, in its entirety from a single molded piece of material in which the inlet and outlet slits are formed, for example, by cutting or molding.
According to another aspect of the invention, a pump for use with a device for containing and dispensing a product may include a body member and a vessel mounted on the body member in a partially-compressed or deformed, first position (i.e., different from a non-compressed, rest position). The vessel may define a variable-volume chamber and may include a first wall and a second wall. The pump may also include an inlet slit on the first wall and an outlet slit on the second wall. The inlet slit may be configured to open one way in response to a decreased pressure in the chamber, and the outlet slit may be configured to open one way in response to an increased pressure in the chamber.
Within the meaning of the present invention, the term xe2x80x9cslitxe2x80x9d may denote an opening obtained by cutting or molding, and of which the edges that delimit the opening are capable of closing it in a substantially sealed manner. In the case of a slit formed by cutting, the cut may be made at right angles to a plane including the wall of the vessel having the slit (i.e., the plane of the slit). Alternately, the cut may be made at another angle. Such a slitted structure may differ from a structure disclosed in U.S. Pat. No. 3,973,700, in which each of inlet and outlet openings consists of a hole having edges that are not capable of closing the opening, but instead form a seat for a flap molded over the plane of the hole, wherein the surface area of the flap is greater than the surface area of the hole.
When the slits of the invention are in the closed position, the edges of the slit may be configured more or less contiguously (i.e., substantially butted up) such that the slits should seal the product off. Thus, in the case of a product of high viscosity, sealing may be achieved in spite of edges that are not completely contiguous. Conversely, in the case of products of low viscosity, contiguous edges may be needed. Optionally, the slit may also be airtight so as to make the pump easier to prime. The substantially contiguous slit arrangement, with the edges abutting more or less tightly in the closed position, may be enhanced by subjecting the slit to a lateral load, that is, one parallel to the plane of the slit.
The edges of such a slit may be capable of parting at right angles to the plane of the slit so as to open the slit in response to a pressure exerted on one side of the slit by the product that is to be dispensed. The edges may return to their closed position when the pressure ceases. When pressure is exerted on the other side of the slit, the edges delimiting the slit may come into abutment against one another to oppose the opening of the slit. The one-way nature of the slit can be obtained by preforming and/or loading the edges of the slit in such a way as to give them an orientation, with respect to a plane substantially including the wall in which the slit is made, that determines the direction in which the slit opens. For example, the slit may be biased closed by preloading the wall of the vessel with a lateral preload.
The slit may be of any shape. For example, the slit may be of elongate shape, or in the shape of a cross or of a star.
Thus, by making the inlet and outlet orifices in the form of slits, a structure may be achieved that can be molded directly in the required shape to form the vessel, that is, in the form of a closed volume in which all that will be necessary will be for the slits to be made, for example, by cutting. The vessel may thus be mounted on the pump body member without the need to produce sealing, other than at the point where the vessel is itself mounted on the body member and where an actuating member is mounted on the vessel.
Optionally, the vessel may be molded in the form of a closed structure in which the inlet and outlet slits are cut. This characteristic, relating to molding in the form of a closed volume, makes it possible to reduce the amount of sealing that has to be achieved when fitting the pump.
By way of example, the vessel may be molded in the form of a cylinder of revolution having two closed ends. One slit may be cut essentially at the center of each of the ends. A structure such as this can be obtained by rotary molding. The cross section of the vessel may be circular, a square, triangular, hexagonal, or another appropriate shape.
The vessel may be elastically deformable, for example, because of its configuration, such as in the form of a bellows, or because of the material of which it is made, such as an elastomeric material, or for both reasons. Thus, the vessel can return to the first position by elastic return exerted by the vessel itself. Alternatively, an auxiliary spring may cause this return.
In one embodiment, the first and second walls of the vessel may be located opposite from one another. Optionally, the first and second walls may be essentially perpendicular, on the one hand, to the direction of the force to be exerted in order to actuate the pump and, on the other hand, to the axis of a passage via which product arrives in the pump. This configuration may be utilized to enhance the one-way operation of the slits. Furthermore, such an arrangement of the slits may make it possible to obtain a pump that is more ergonomic, as well as simpler and more economical to produce. Also, the inlet and outlet slits may be aligned along an axis of the vessel (e.g., a longitudinal axis of the vessel.).
The vessel may be made of a material chosen from thermoplastic and polymerized elastomers. The material may be chosen from nitriles, silicones, natural and synthetic latices, EPDMs, polyurethanes, blends of polypropylene and one of SIBS, SEBS and EPDM, very-low-density polyethylenes, blends based on polyester glycols (TPU), blends based on polyether glycols (PEBA and COPE), and flexible polyvinyl chlorides (PVC). Such a material may have a hardness of, for example, from 20 Shore A to 40 Shore D, and optionally from 40 Shore A to 75 Shore A. The elasticity of the material may range, for example, from 0.5 to 5 MPa and optionally from 0.8 to 2 MPa (tensile stress at 100% elongation).
According to another embodiment, the deformation of the vessel from the first position to the second position may result from an elastic deformation of at least one side wall separating (i.e., between) the first and second walls. The deformation may be in response to pressure exerted on the vessel, optionally by way of an actuating member, and the return of the vessel to the first position may be by elastic return of the side wall thus deformed.
The vessel may be placed inside a rigid or semi-rigid body member. The body member may include a snap-fastener or screw-fastener, allowing the pump to be fixed onto a container containing a product that is to be dispensed. A body member such as this may be made of polypropylene or polyethylene. The body member may include a passage having one end that opens proximal to the inlet slit of the vessel, and another end that opens into the container. Optionally, a dip tube may be mounted on the passage, for example, by force-fitting. A free end of the dip tube may be arranged essentially at the bottom of the container.
According to yet another embodiment of the invention, the vessel may be mounted on the body member of the pump with an axial preload causing predeformation of the side walls so as to form a convexity into the vessel when viewed from an inside of the vessel. Such predeformation may be configured to encourage or assist the vessel to deform from the first position to the second position. Optionally, at the time of molding, the vessel may be preformed so that the side walls have a slightly convex shape when viewed from inside the vessel when the vessel is in a non-compressed, rest position. The convex shape may be accentuated at the time of assembly by the axial load.
According to another embodiment of the invention, the vessel may be mounted on the body member of the pump with a lateral preload configured to bias the inlet and outlet slits toward a closed position (i.e., encourage or assist the one-way nature of the slits). The inlet slit may be delimited by at least two edges, the edges being, under the effect of the lateral preload, moved with respect to the mean plane of the first wall inward with respect to the variable-volume chamber. With a configuration such as this, the edges delimiting the inlet slit may be capable, in response to a raised pressure in the chamber, of coming into abutment against one another so as to prevent the slit from opening towards the container. The movement of the edges of the slit towards the inside of the vessel may be encouraged or assisted by preforming of the vessel, for example, at the time of molding.
In the same way, the outlet slit may be delimited by at least two edges. The edges under the effect of the lateral preload may be moved with respect to the mean plane of the second wall, outward with respect to the chamber, toward the actuating member. Thus, in response to decreased pressure in the chamber, the edges delimiting the outlet slit may be capable of coming into abutment against one another so as to prevent the outlet slit from opening toward the inside of the vessel. The outward movement, with respect to the vessel, of the edges of the slit may be encouraged or assisted by preforming of the vessel, for example, at the time of molding.
The first wall and/or the second wall may be preformed, such as at the time of molding of the vessel, so as to encourage or assist the edges of the corresponding slit to move as desired in response to the lateral preload.
A passage may be provided to allow air to be taken into the container when the vessel returns from the second position to the first position. Such a passage may be made in the body member of the pump, with a first end of the passage opening into the container and a second end of the passage being closed off by the vessel when the latter is in the first position. The passage may be at atmospheric pressure when the vessel is in the second position.
The vessel may be fixed, for example, by bonding or welding, on the body member of the pump. Optionally, the vessel may be fixed inside the body member. Alternatively, the vessel may be force-fitted into the pump body member, and thus held by clamping.
The actuating member of the pump may be configured in the form of a push-button. The actuating member may include a passage, of which a first end opens facing adjacent to the outlet slit of the vessel and a second end opens to at least one product-dispensing orifice. Such a push-button may be formed, for example, of a thermoplastic material such as the polyethylene or polypropylene type or of an elastomeric material identical to or different from the material that forms the vessel. The pump according to the invention may include means capable, in a so-called xe2x80x9ctransportxe2x80x9d position, of preventing its operation. Such means are well known and therefore require no additional detailed description.
According to another aspect, the invention may include a device for containing and dispensing a product. The device may include a container configured to contain a product and a body member attached on the container. A vessel defining a variable-volume chamber may be mounted on the body member. The vessel may include a first wall and a second wall. The device may also include an air passage on the body member. The air passage may include a first end and a second end. The first end may open into the container, and the second end may be selectively opened and closed by the vessel. An inlet slit may be on the first wall of the vessel, and an outlet slit may be on the second wall. The inlet slit may be configured to open one way in response to a decreased pressure in the chamber, and the outlet slit may be configured to open one way in response to an increased pressure in the chamber.
In one embodiment of the device, the vessel may be configured to deform from a first position occupying a first volume to a second position occupying a second volume in response to a pressure applied to the vessel. The second end of the air passage may be closed off by the vessel when the vessel is in the first position, and the second end may be opened to atmospheric pressure when the vessel is in the second position. In another embodiment, the body member may be fixedly attached on the container, for example, by snap-fastening or screw-fastening.
In yet another embodiment, the body member may include an additional passage. The additional passage may include a first end opening proximal to the inlet slit and a second end opening into the container. The device may optionally include a dip tube mounted on and/or in flow communication with the additional passage. The dip tube may include a free end configured to extend substantially to a bottom of the container.
The container may contain, for example, a cosmetic or dermo-pharmaceutical product, such as a hair product, a sun-protection product, a personal hygiene product, a make-up product, and/or a care product. The product may be, for example, in the form of a milk, an emulsion, a gel, or a cream.
According to yet aspect of the invention, a method of dispensing a product may include providing a pump as described above, actuating the pump to dispense product from a container, and directing the dispensed product to a surface region. The surface region may be, for example, an external body member portion. The product may be, for example, a cosmetic or dermo-pharmaceutical product, such as a hair product, a sun-protection product, a personal hygiene product, a make-up product, and/or a care product. The product may be, for example, in the form of a milk, an emulsion, a gel, or a cream.
Apart from the provisions explained hereinabove, the invention may include a certain number of other arrangements that will be dealt with more fully hereinafter with regard to some embodiments that are described with reference to the drawings appended hereto, but which are not in any way limiting. It is to be understood that both the foregoing description and the following description are exemplary, and are intended to provide further explanation of the invention as claimed.